Abstract:

Objective To establish a convenient ¹³C-breath test system in live mice, and investigate the value of ¹³C-methacetin breath test (¹³C-MBT) in the diagnosis of acute liver damage of mice with domestically synthesized ¹³C-methacetin. Methods Domestically synthesized ¹³C-methacetin was prepared from acamol by methylation. Abdominal injection of CCl₄ was adopted to duplicate acute liver damage of mice, then the mice were housed under normal laboratory condition for a whole month to gain recovery, which were indentified by hepatic pathological examinations and biochemical tests of liver function. After fasting, the mice were orally administered ¹³C-methacetin, and the expired air was collected at various time points. Infrared spectrometer was employed, and delta over baseline (DOB) curves of ¹³C-exhalation were drawn. Results Six to eight min after administration of ¹³C-methacetin, the rate of ¹³C-exhalation peaked in control group (51.9±2.04), and decreased thereafter. Sixteen min after administration of ¹³C-methacetin, the rate of ¹³C-exhalation peaked in model group (26.37±5.74), and decreased thereafter. There were significant differences between these two groups (P<0.05). There was no significant difference in peak value and time to reach the peak on DOB curves of ¹³C-methacetin breath test after the two groups of mice were housed under the same condition for a month (P>0.05). Conclusion ¹³C-MBT facilitates the collection and evaluation of ¹³CO2 in the expired air of live mice, and yields precise reflection of alterations of liver function in acute liver injury and functional recovery.

Key words: breath test, mice, domestically synthesized ¹³C-methacetin